The Haber-Bosch Process: Nitrogen Fixing the World

All living things require appropriate nutrients in order to grow, to flourish, and to procreate to ensure the continuity of the species. Nitrogen is one such nutrient, an element that is an important component of photosynthesis and genetic material such as DNA, RNA, and protein. But where does it come from? Nitrogen makes up more than three quarters of the air we breathe. But in order to be usable to living things, one nitrogen atom must be bonded to three hydrogen atoms to form ammonia. In this form, the nitrogen is fixed and is in a form able to carry out its vital roles. But unfortunately, nitrogen atoms in the air prefer to bond with each other. And when two nitrogen atoms bond, they form a very strong triple bond. This bond is very difficult to break and therefore renders the nitrogen in the air useless to living things. Ironically, this abundant element is actually one of the most difficult nutrients to obtain in usable form and is therefore the most limiting factor in plant growth. For most of human history, the soil's nitrogen supply typically came from animal corpse, dead plants, manure, and guano. Other sources included plant bacteria that replenished the soil's nitrogen, legumes, and even lightning, which provided the intense energy required to break the nitrogen bonds. But in the 19th century, the greatest source of nitrogen by far was Chilean saltpeter. At the time, this source, derived from rock deposits containing sodium nitrate, fulfilled well more than half of the world's nitrogen needs. However, the saltpeter supply wasn't expected to last more than another 30 years. More and more people began to acknowledge the diminishing supply of nitrogen. And in September of 1898, Sir William Crookes, president of the British Association for the Advancement of Science, delivered an address at its annual meeting. He spoke to a large audience of chemists, warning that the world was facing starvation since the old ways of agriculture would no longer suffice in meeting the food needs of a growing population. Crookes predicted widespread famine within two to three decades since farmland was becoming more and more scarce and the population was growing. Crookes told his audience the solution was nitrogen, since nitrogen fertilizers would make it possible to grow more wheat on less land. This was a matter of having enough to eat. This was a matter of life or death. Crookes' speech became wildly popular across Europe. Scientists began the quest to discover a reliable method for fixing nitrogen with the goal of commercializing it to use in crop fertilizers. Months turned into years as the answer continued to elude the hard-working yet unsuccessful chemists. It wasn't until nearly a decade after Crookes' speech that the possibility of success finally became tangible. One chemist was on the verge of changing the course of history. His name was Fritz Haber. Haber worked in a laboratory in the Technical University of Karlsruhe, Germany. In March 1909, Haber was finally able to produce a cubic centimeter of ammonia in his lab. This was a monumental discovery, for ammonia would serve as the perfect ingredient for the creation of synthetic nitrogen fertilizers. However, successfully combining nitrogen with hydrogen worked in the lab for Haber, but would not adequately work on a commercial scale. After Haber's discovery was announced, Carl Bosch, an engineer at Germany's largest chemical company, BASF, was called upon to solve the technical issues of Haber's lab design. With his ingenious modifications, chemical production of ammonia was initiated in 1913 at the first commercial ammonia factory built by BASF in Oppau, Germany. The Haber-Bosch process was born. This process did not just help to feed Earth's growing population, it was also responsible for an exponential population boom. The profound impact of the discovery was clearly demonstrated when the president of the Royal Swedish Academy of Sciences presented Haber with the 1918 Nobel Prize in Chemistry. Similarly, Carl Bosch was awarded the Nobel Prize in Chemistry in 1931 for his contributions to the Haber-Bosch process. Despite the grand significance of the Haber-Bosch method for nitrogen fixation, the economy during the years between the two world wars prevented the process from reaching its full potential immediately. However, after World War II, ammonia production and fertilizer use gradually increased. When technical advances led to more economical ammonia-producing facilities in the 1960s, demand began to grow exponentially. Today, global fertilizer use is above 200 million tons per year. Other achievements in agriculture such as high yield, hardier crop varieties, irrigation and pesticides cannot compare to the profound contribution made to agriculture and the world by the Haber-Bosch process. Vaclav Smil, world-renowned Haber-Bosch expert, confirmed this. It's to make the protein. So without large application of fertilizers, no Green Revolution, no increase in yields, and no possibility to have as many billions of people as we have now. This is why I keep concluding and telling people to their surprise that this is the most important invention of 20th century or of all times because, you know, everything starts in people as far as we are concerned. You could not have that many people without having that much food, without having that much fertilizer. But humanity's reliance on the Haber-Bosch process has had some serious ramifications for the environment. Excess nitrogen runoff into water bodies and into the atmosphere is upsetting nature's balance and are proving toxic to the environment. Dr. James Galloway, biogeochemical professor at the University of Virginia, adds, The Haber-Bosch process converts into the atmosphere to ammonia and it is then used as fertilizer. The good news is it's feeding a large percent of the world population. The bad news is that much of it is lost to the environment after the food production process. And this is contributing to smog, to acid deposition, to global change, to dead zones in the coast, to stratospheric ozone depletion. However, solutions to these environmental issues remain elusive as no substitutes for the Haber-Bosch process are currently available to sustain Earth's ever-growing population. When Crookes initially spoke at the end of the 19th century, the global population was 1.6 billion. It is now approximately 7 billion and growing. This huge population increase comes as a direct result of the Haber-Bosch process, which is responsible for more than 99% of the world's synthetic nitrogen fertilizer production and consequently more than half of the nitrogen added to soil. Two out of every five people around the world are sustained by the increased crop growth that relies on synthetic fertilizer. About half of the nitrogen in each of our bodies originated in a factory that utilizes the Haber-Bosch process. Every single person on Earth has been directly or indirectly affected by it. And as the projected world population is expected to rise over the course of our lifetimes, the Haber-Bosch process is here to stay. With such a powerful impact on the world, the Haber-Bosch process has served as the major turning point in our planet's history, as it has nourished crocs and consequently billions of humans on Earth.